Four Iranian police officers have been killed in the southeastern Sistan-Baluchistan province, the scene of other recent deadly violence, official media said.

"The incident, at a traffic police station on the Iranshahr-Bampour highway, caused the martyrdom f police officers," regional police chief Major Alireza Sayyad told IRNA news agency, adding that an investigation was underway.

Iran has been rocked by more than seven weeks of nationwide protests over the death of 22-year-old Kurdish Iranian woman Masha Amini while in the custody of the Tehran morality police.

Alongside that unrest, clashes also broke out in Sistan-Baluchistan, which borders Pakistan and Afghanistan, sparked by the alleged rape of a local teenage girl by a police chief.

On September 30 in Zahedan, the provincial capital, dozens of protesters and six members of the security forces were killed, according to the authorities.

Poverty-stricken Sistan-Baluchistan has long been a flashpoint for clashes with rebels from the Baluchi minority, Sunni Muslim extremist groups and drug smuggling gangs.